Insect infestation is a primary cause of crop loss throughout the United States. A wide variety of chemical pesticides has been relied upon in the past to control insect pests. However, environmental concerns as well as consumer safety concerns have led to the de-registration of many pesticides and a reluctance to use others on agricultural products which are ultimately consumed as food. As a consequence, there is a desire for the development of alternative biological control agents.
Pheromones are chemicals which are secreted outside the body of insects can be classified according to the type of behavioral reaction they induce. Pheromone classes include aggregation pheromones, sexual pheromones, trail pheromones, and alarm pheromones. Sex pheromones, for example, are typically secreted by insects to attract partners for mating.
When pheromones are dispersed on leaves of a crop plant, or in an orchard environment in small quantities over a continuous period of time, pheromone levels reach thresholds that can modify insect behavior. Maintenance of pheromone levels at or above such thresholds can impact insect reproductive processes and reduce mating. Use of pheromones in conjunction with conventional insecticides can therefore reduce the quantity of insecticide required for effective control and can specifically target pest insects while preserving beneficial insect populations. These advantages can reduce risks to humans and the environment and lower overall insect control costs.
Despite these advantages, pheromones are not widely used today because of the high cost of active ingredient (AI). Even though thousands of insect pheromones have been identified, less than about twenty insect pests worldwide are currently controlled using pheromone strategies, and only 0.05% of global agricultural land employs pheromones. Lepidopteran pheromones, which are naturally occurring compounds, or identical or substantially similar synthetic compounds, are designated by an unbranched aliphatic chain (between 9 and 18 carbons) ending in an alcohol, aldehyde, or acetate functional group and containing up to 3 double bonds in the aliphatic backbone. Improved methods for preparing lepidopteran insect pheromones and structurally related compounds are needed. The present invention meets this and other needs.